1/4 cup (60ml) warm water, 110 – 120 degrees
1 Tbsp active dry yeast
3/4 cup (180ml) buttermilk, at room temperature*
2 large eggs, at room temperature**
1/2 cup (100g) + 1/2 tsp granulated sugar, divided
1 tsp salt
1/2 tsp vanilla extract
6 Tbsp (85g) unsalted butter, diced into 1 Tbsp pieces and melted
3 1/2 – 4 cups (17.5 oz – 20 oz) bread flour (I recommend King Arthur)
6 Tbsp (85g) unsalted butter, well softened
1 cup (210g) packed light brown sugar
2 Tbsp (13g) Saigon cinnamon
Cream Cheese Icing
1/4 cup (56g) unsalted butter, softened
3 oz. cream cheese, softened
1/2 tsp vanilla extract
1 1/2 cups (190g) powdered sugar
Pour water in a the bowl of an electric stand mixer, pour in yeast and 1/2 tsp sugar and whisk well. Let rest 5 – 10 minutes to proof (if it doesn’t puff up your water was either too hot or the yeast is bad and the rolls won’t rise).
Add in buttermilk, eggs, 1/2 cup granulated sugar, salt, vanilla and 6 Tbsp melted butter. Fit mixer with whisk attachment and blend mixture until combined.
Pour in 2 1/2 cups of the flour and mix until well combined. Switch to a hook attachment then add another 1 cup flour. Knead mixture until combined.
Continue to knead on moderately low speed about 5 – 6 minutes while adding a little more flour as needed to reach a soft and moist dough (Dough shouldn’t stick to the sides of the bowl but does stick to the bottom. I ended with 3 3/4 cups or 18.75 oz, but I am in a fairly dry climate so in a humid climate you may need a little more. Also note I use the scoop and level method when measuring in cups).
Transfer dough to an oiled bowl, cover with plastic wrap and let rise in a warm place until doubled in volume, about 1 1/2 hours.
Butter a rimmed 15 by 10-inch jelly roll pan (not a standard size cookie sheet!) then line with parchment paper***. Butter parchment paper and set aside.
Punch dough down. Dust a working surface lightly with flour and turn dough out onto surface. Sprinkle top of dough with a little flour then roll dough out into an 20 by 18-inch rectangle.
Spread 6 Tbsp butter evenly over entire surface (just use your hands). In a small mixing bowl whisk together brown sugar and cinnamon. Sprinkle and spread brown sugar mixture evenly over butter layer (try to leave about 1/2-inch border uncovered along all edges).
Beginning on an 18-inch side tightly roll dough into a cylinder. Pinch the seam to seal (brushing a little egg white underneath helps if needed).
Cut into 12 equal portions using a large sharp knife (they should be 1 1/2-inch each). Arrange rolls, spacing evenly apart on prepared baking sheet.
Cover with plastic wrap (leave plastic it a little loose but be sure it fully encloses to keep air out. Also see notes for overnight method as this would be the point to chill**).
Let rise in a warm place until doubled in volume, about 1 1/2 hours. Preheat oven to 375 degrees near the last 20 minutes of rolls rising.
Bake rolls in preheated oven until centers are no longer doughy, about 18 – 22 minutes (center should be 185 degrees on an instant read thermometer). If needed during the last 5 minutes of baking you can tent with foil to prevent excess browning, all ovens vary.
While rolls are baking in a medium mixing bowl using an electric hand mixer whip together butter and cream cheese until smooth and fluffy. Add in vanilla and powdered sugar and whip until light and fluffy.
Spread icing over hot from the oven rolls. Rolls are best served warm. If you have leftover rolls store in an airtight container once cool and rewarm individually on a plate in microwave for about 15 seconds or until soft and warm.